create list of unique values

[blackbox]

I know the Advanced filter does this but I couldn't get it to work in vba, so I tried the following and couldn't get it to work either
In column A I have values starting at row 4, ranging up to row 1004.

in coulumn Q (starting at row 3) I'd like a list of unique entries from column A

I know this line is my problem

If Range("A" & I) <> Range("Q4:Q30") Then

but i'm not sure how to compare against all values in a range

Sub FilterSymbol()
Dim I As Integer
Dim X As Integer
X = Range("O2")
I = 4

Do
If Range("A" & I) <> Range("Q4:Q30") Then
Range("Q" & I) = Range("A" & I)
I = I + 1
Else: I = I + 1
End If
Loop Until I >= X
 
End Sub

 

[blackbox]

i've closed and reopened it several times. only picks up 1 value (A4)

im running office XP